This Franz Xaver studied in Regensburg with Riepel. Count Philipp Karl of Oettingen-Wallerstein sent him to study with Johann Stamitz, Richter, and Holzbauer in the major musical center of Mannheim. The Count ordered him back in 1754 because he was short of musicians. The Count evidently promised Pokorny the position of choral director.
The Count did not keep this promise, even when Pokorny petitioned him for it in 1766. Pokorny might have been fed up by now, for he sent what we would call a job application that year to the court of Thurn and Taxis at Regensburg. He was admitted as a member of the royal Kapelle that year, and evidently stayed there; his tombstone records that he was a musician of the royal chamber.
There are difficulties in the attribution of music to Pokorny. Over 100 symphonies have been credited to him, of which as many of 57 are the subjects of disputes as to who really wrote them. The symphonies attributed to him are usually four-movement works for strings, two flutes, and two horns, with occasional use of clarinets, oboes, timpani, and trumpets. The melodies are in a popular style, and he tends to use sequential repetition in place of real symphonic development.
His son Bonifaz (Franz Xaver Karl, 1757 - 1789) was an organist and priest. He also composed, but none of his music survives. Another son, Joseph Franz, was evidently a minor musician. Beate Pokorny, a horn virtuosa who was very popular in Paris' Concerts Spirituels in the 1780s, was not Pokorny's daughter, but may have been his sister.